The invention relates to a machine for automatically attaching cover slips to microscope slides having specimens for microscopic examination, comprising a first magazine for microscope slides, a second magazine for cover slips, and a reciprocating transport means for transport of slides and cover slips from the respective magazines to a working station comprising a pumping means for application of adhesive to slides, and a lifting means for lifting and placing of a cover slip on a slide which is provided with adhesive.
Such application of cover slips or cover glasses to microscope slides especially is carried out in hospitals and in medical laboratories, wherein microscope slides having different types of medical specimens must be covered by protective cover slips. The tissue specimens which are to be examined, are either histologic specimens in the form of thin cuts (3-4 xcexcm thick) or cytologic smears. Both types of specimens are coloured in a stainer prior to sealing in order to bring out the cell structure. In this connection it is usual to make use of a basket which contains a number of slides, as a carrier during the staining as well as the sealing process.
On the market there exist several types of machines or apparatuses carrying out gluing of cover slips on slides. An apparatus or machine of the type stated in the introduction is, for example, known from the international patent application No. PCT/NO93/00188 (WO 94/14097). In this apparatus, a slides magazine is arranged next to a cover slips magazine, and a reciprocating sliding means provides for simultaneous feeding of a slide and a cover slip to a position next to each other on a working station where the cover slip is placed on the slide after application of adhesive thereon. The cover slips magazine here consists of a wall-forming frame member surrounding a stack of cover slips which are all the time supported by the sliding means, the sliding means having a recess which, in an initial position, receives the lowermost cover slip in the stack, so that the sliding means brings individual cover slips to the working station. Since the stack of cover slips are supported by the sliding means, the stack will remain on the sliding means if the magazine frame member is lifted therefrom. Accordingly, a loaded cover slips magazine here is not a separate unit which is able to be exchanged and replaced by another preloaded cover slips magazine containing a different cover-slip size.
In machines and apparatuses of the topical type it is important that the period from the time when the tissue specimens are taken out from the colouring process until they are sealed, is as short as possible. A dehydration of the specimens results in a poorer sealing and readability of the tissue condition, air bubbles then arising in the tissue. In other words, it is important that the machine works as quickly as possible. Further, there are several laboratories which use different cover-slip sizes, and a rapid change from one cover-slip size to another here is of great importance. A cover-slip attaching apparatus of the type utilizing tape for sealing, does not have said drawbacks, the apparatus working very quickly and not being dependent on cover slips of a certain size. However, in addition to being prone to getting scratches, the tape has the drawbacks that it is not planar if the tissue specimen is not planar, and that in some cases it has a tendency to loosen over time. Therefore, there is a clear tendency that more and more laboratories want to use cover slips which are manufactured from glass. It is important that the cover slip is placed in the glue with a very calm movement and such that air bubbles are not captured under the cover slip.
In addition to the fact that the known machines and apparatuses on the market do not have such a high working speed as desirable, the are relatively big. Further, they have a poor accessibility for removal of glue and glass residues and for other maintenance which is necessary
It is an object of the invention to provide a machine of the topical type having such a high working speed that microbubbles are avoided without additional wetting of the tissue with unnecessary solvent being necessary, at the same time as one avoids getting air bubbles in the tissue.
Another object of the invention is to provide such a machine which enables a rapid change from one cover slip size to another.
A further object of the invention is to provide a machine which is very small and compact and also silent-running, and which has such a design that the user is protected against glass fragments which may spatter around in case of accidental crushing of cover slips, as well as against inhalation of solvent gases.
A still further object of the invention is to provide a machine having a construction giving good accessibility for daily cleaning, operation and service, in order to achieve a substantial improvement of the operational security.
For achieving the above-mentioned objects there is provided a machine of the introductorily stated type which, according to the invention, is characterized in that the two magazines are located on opposite sides of the transport means, and that the transport means is arranged to carry a slide from the first magazine to the working station in an outgoing movement from a home position, and to carry a cover slip from the second magazine to the working station in a return movement, the lifting means being arranged to lift a cover slip from the transport means before the latter is allowed to start its outgoing movement, and further is arranged to place a cover slip on the slide on the working station with terminated outgoing movement of the transport means and after application of adhesive to the slide by the pumping means, the transport means being arranged to bring the slide with attached cover slip back to the first magazine during its return movement, at the same time as a new cover slip is carried from the second magazine to the working station.